1. Field of the Invention
The present invention relates to an apparatus and method of reducing slip or slide of a railcar.
2. Description of the Related Art
To reduce slip or slide of a wheelset, a railcar may include an apparatus of reducing torque applied to the wheelset that is slipping or sliding.
In JP2005289172A, a highest value among speeds of a plurality of wheels is regarded as a speed of a railcar, and deceleration of each of the wheels is calculated. Regarding the wheel whose deceleration is not more than a threshold, a difference between the speed of such wheel and the speed of the railcar is calculated as a sliding speed of this wheel. Regarding the wheel whose sliding speed exceeds the threshold, braking torque applied to such wheel is reduced.
According to this method, it is difficult to prevent or quickly solve “all-wheelset synchronous slide.” The all-wheelset synchronous slide denotes a phenomenon in which all the wheelsets are substantially the same in the number of rotations as one another and are sliding. If the all-wheelset synchronous slide occurs, all the wheels actually slide on a rail, but the differences among the numbers of rotations of the wheelsets become extremely small values, and the sliding speed becomes lower than the threshold. Therefore, the braking torque applied to the wheels is not reduced, and the slide of all the wheels continues.